Educated at Lenzie Academy,[4] he left the school at the age of 15 "under a bit of a cloud" without any qualifications or school prizes.[5] He led a paper-boys' strike at the age of fifteen,[6] and had a number of jobs after leaving school, including a seaman, a local government manual worker, and a kitchen worker.[7] He was a councillor for Abram ward, Wigan, from 1982 to 1987.[8]

McCartney became the MP for Makerfield following the 1987 general election. He was one of the founders of the All-Party Parliamentary Rugby League Group the same year, and was its first chairman.[9] He held a number of positions during Labour's period in opposition, and was variously a spokesman on Health, Employment, Education and Social Services. In 1994, he ran John Prescott's successful campaign to become Labour's Deputy Leader. McCartney was one of the shortest MPs, standing five feet, one inch tall. He described himself on his parliamentary notepaper as the "Socialist MP for Makerfield".[10]

McCartney was made Minister of State at the Department of Trade and Industry (DTI) following the 1997 general election when Labour came to power.[7] While at the DTI he introduced a major package of new employment rights that included whistleblowing protection and the National Minimum Wage and the first-ever right to paid holidays,[7] and steered the Competition Act through Parliament. As a former low-paid worker who had been sacked upon asking for a pound pay rise after having a child, McCartney later described the minimum wage as very important to him, saying that he would have "died in the ditch" for it.[7] During this time he was also responsible for employment relations, the Post Office, Company Law and inward investment.

Between October 2004 and October 2005, he was Chairman of the Labour Party in two capacities - as the Party Chair (appointed by the party's leader) with a seat in the Cabinet, and as the Chair of the National Executive Committee (elected by the members of the NEC). He was also chair of the party's National Policy Forum, which formulates Labour party policy.[14] The NPF also oversaw the 'Big Conversation' project, which saw the Labour Government try to consult the general public on the future direction of party and government policy. Trusted by both leadership and membership, he was seen as a key link between the Government and the wider Labour movement.[citation needed]

He worked to make the role of Party Chair a voice for Labour Party members within the Labour Government. As architect of the Warwick Agreement by Labour's National Policy Forum, he was a key figure in co-ordinating the election manifesto for Labour's third term general election campaign. In 2006 he took a three-month leave of absence following heart bypass surgery,[15] and publicly told of his fight to lose weight for the sake of his health. His return to frontline politics was marked by his speech to the Labour Party 2006 Spring Conference in Blackpool in which he shed a tear while celebrating 100 years of the Parliamentary Labour Party. He returned to government as Minister of State for Trade in May 2006, attending Cabinet but not voting at it, but stepped down in 2007 when Gordon Brown became Prime Minister.

Beginning in October 2007 McCartney worked with the construction, engineering and nuclear energy company Fluor, providing them with advice in anti-corruption and business ethics policies; political, economic, environmental and regulatory issues; and outside relations including working with trade unions.[16] After details of this position were published in The Independent McCartney stated unequivocally that he personally receives none of the remuneration for this role, instead using part of the fee to employ someone in the House of Commons from his Makerfield constituency. The remainder is used to support the Women's Interlink Foundation,[17][18][19] a charity based in India which rescues street children and disadvantaged women who are exposed to poverty and sometimes at the risk of rape and murder, providing them with clean drinking water, health treatments, housing and education.

In August 2008, after admitting that some of his claims for furnishing his second home were "inappropriate," McCartney repaid £15,000 of expenses claimed for among other items, a dining table, 18-piece dinner set and champagne glasses. McCartney has asked for the review and although only a portion of the amount was deemed excessive McCartney said he felt strongly that the full amount should be returned. McCartney commented that as a senior minister he held meetings at home and "had to feed guests."[12][20][21]

In May 2009 after stepping down citing health issues, McCartney said his family had urged him to step down following a further bout of illness after his 2005 heart surgery, and that he was also being treated for disc injury and was possibly facing further surgery.[22][23][24]

He was married firstly to Jean (née Murray), with whom he had son Hugh and daughters Yvonne and Karen, later divorcing.[26] Hugh died aged 23 of a drugs overdose in 1999 in his flat in Parkhead.[27]

Hugh, known as "Shug",[28][29] had battled drug addiction since his teenage years. Only recently released from prison, he had been trying to break his habit.[30] In 2002, McCartney gave an interview with the Sunday Herald discussing his son's experiences in the justice system and how he [Ian McCartney] believed "the way we deal with addicts sentenced his son to death".[31] In 2003, McCartney stated in an interview that he still breaks down over the death of his only son.[32]

McCartney's second and current wife is Ann Kevan Parkes, whom he married in 1988.[26][30][33]